Our proposed research is to study the aging effects and some properties of the low molecular weight proteins from cataractous human lens. We are especially interested in the heavy and light molecular weight gamma crystallins, beta-s crystallin and additional gamma crystallin which possessed an unexpected molecular weight of 11,000. Our recent studies revealed that the aging effects observed in the low molecular weight human normal lens proteins were generally similar to those observed in the bovine lens. However our preliminary studies found that a shoulder peak of light molecular weight human normal lens gamma crystallin fraction which had a molecular weight of 11,000 appeared more abundant in the cataractous lens cortex and formed an additional peak. The high degree of heterogeneity of these low molecular weight human lens proteins was observed. The most characteristic change in the human normal low molecular weight proteins was, as was the case in bovine lens, that the heavy gamma crystallin became more prominent with age. We wish to pursue these observation with human cataractous lenses in detail. Biochemical analyses including flat bed & column electrofocusing and immunochemical studies will characterize these proteins in human cataractous and normal lenses.